Fig. 7: A model depicting the mechanisms by which these early grains suppress these unfertilized ovaries to consolidate their advantage for development.
From: Siblicide between fertilized and unfertilized ovaries within the maize ear
When the ear is asynchronously pollinated, these early grains may emit some suppressing signal molecules that are transmitted into these unfertilized ovaries. Upon receiving the signals, these unfertilized ovaries synthesize excessive levels of auxin and JA with activated auxin signaling transduction, while reducing MAPK signaling. Consequently, the processes of cell wall degradation, dehydration, and senescence are initiated, impeding the viability maintenance of these ovaries. On the contrary, these early grains were promoted with increased sugar availability and activated sugar and MAPK signaling for sugar utilization and cell proliferation. The signal molecule transmitting among grain/ovary siblings has been proposed in current and many recent studies but is still unvalidated. TPS trehalose 6-phosphate synthase, T6P trehalose 6-phosphate, JA jasmonic acid, MAPK mitogen-activated protein kinase.
